The present invention deals with systems and methods for actuating an implantable medical device. While the invention could be applied in the context of a variety of medical devices, the present description, for the sake of brevity, will be focused primarily on implantable stents and filters. Accordingly, the present invention deals with systems and methods for remotely actuating an implantable stent or an implantable filter.
Implanted medical devices are susceptible to becoming clogged, encrusted or otherwise compromised after placement in the various vessels, tubes, ureters and organs of the body.
Generally, the long term patency of stents in-vivo can be compromised in instances where agglomeration or encrustation is encountered. For instance, while intracoronary stenting has proven to be an arguably effective tool for coronary revascularization, the incorporated stents are susceptible to in-stent restenosis, which significantly compromises long-term effectiveness of the procedure.
Filters tend to be particularly susceptible to encrustation caused from precipitation of fluids that pass through them. This effect tends to compromise the long-term patency of filters in-vivo. Certain in-vivo filters, such as vena cava filters where blood clots tend to aggregate, are particularly vulnerable to agglomeration and encrustation.
A variety of methods have been developed and have proven to be at least partially successful in increasing the post-implantation effectiveness of stents and filters. Specialized coatings, material selection and placement techniques have been known to contribute in various ways to preventing a gradual loss of patency or effectiveness of implanted stents and filters. In addition, various acoustic ablation devices, transducers and extracorporeal acoustic generating devices have been utilized for the same purpose. These methods typically either require threading catheters into vessels, which may be undesirable, or require the use of expensive external equipment, such as shock wave lithotriptor systems, to affect and/or monitor the condition of an implanted device. Systems and methods that effectively prevent gradual losses of patentcy or effectiveness of implanted appliances, especially systems and methods that are minimally invasive and inexpensive to manufacture, are desirable.
One aspect of the present invention pertains to a medical device vibratory activation system. The system includes an implantable appliance comprising a conductive material and a signal producing mechanism having a portion configured to be located relative to the implantable appliance. The signal-producing mechanism is also configured to generate a signal that interacts with the conductive material in the implantable appliance to induce a motion of the implantable appliance.
Another aspect of the present invention pertains to a method of diagnosing a condition of an implanted medical appliance. The method comprises implanting a medical appliance that comprises a conductive material; positioning a portion of a signal-producing mechanism in a location proximate the implanted medical appliance; inducing a motion of the implanted medical appliance by utilizing the signal-producing mechanism to generate a signal capable of motion-producing interaction with the conductive material; sweeping the signal over a plurality of frequencies, wherein at least one of the frequencies is a key frequency that induces a resonant response by the implanted appliance; and identifying the key frequency.
Yet another aspect of the present invention pertains to an implanted conductive appliance electromagnetically coupled to an extracorporeal signal-producing mechanism. The extracorporeal signal-producing mechanism is configured to induce a reaction by the implanted conductive appliance.